1. The Field of the Invention
This invention relates to syringe systems that are used for storing and dispensing materials therefrom. More particularly, the present invention relates to a dental syringe system that provides for controllable doses of a solid but pliable light activated dental composite and that prevents substantial discoloration of the composite material when the composite material is being applied to the dental construction.
2. The Prior State of the Art
The prior art addresses syringes which are constructed to progressively extrude solid, yet pliable materials such as composite materials that are used in clinical dental procedures. The extrudent in dental procedures may be a light-cured composite material. Once the material is extruded from the syringe, it must be directed to the site where the material is to be applied. The material may be extruded directly onto an application site by contacting the site directly with the tip of the syringe. However, such direct placement may cause contamination of a large portion of the material when the application site is not sterile. Thus, direct application is not the best means of application of the extruded material where concern for cross contamination exists and adequate safeguards are not present.
Various devices have thus been developed to facilitate the application of solid, yet pliable materials. An example of such a device is shown in FIGS. 1A, 1B, and 1C. FIG. 1A shows a syringe apparatus 100 the main elements of which are a barrel 10, a threaded plunger engager 40, a plunger 70, a plug 82, and a cap 98. Such a syringe is disclosed in detail in U.S. Pat. No. 5,618,273. U.S. Pat. No. 5,618,273 describes in detail the configuration of threaded plunger engager 40 and plunger 70 and how threaded plunger engager 40 facilitates operation of plunger 70.
As shown in FIGS. 1B and 1C, the barrel 10 terminates at its outlet end 16 with a delivery tip of the type disclosed in U.S. Pat. No. 5,387,103 and in U.S. Pat. No. 5,618,273. That is, barrel 10 further comprises a divider 80 for sectionalizing and individually compartmentalizing the composite material. Divider 80 has cutting plates 86 which are aligned on a longitudinal axis. Each cutting plate 86 has a leading beveled edge 90, which serves to cut the pliable material into individualized sections. This configuration enables each of the individualized sections of the material to be contained in a separate compartment. Each separate compartment accommodates the removal of a selected portion of the sectionalized and compartmentalized part of the material in the manner discussed in detail in U.S. Pat. No. 5,387,103; U.S. Pat. No. 5,603,701 and U.S. Pat. No. 5,618,273. Syringes having this design are presently sold by ULTRADENT PRODUCTS, INC. of South Jordan, Utah and the unique divider configuration is known as the QUADRASPENSE(copyright) delivery feature. Ultradent Products, Inc. sells a variety of dental compositions in syringes that utilize the QUADRASPENSE(copyright) delivery including VITALESCENCE(copyright) restorative material and AMELOGEN(copyright) restorative material.
Generally, as shown in FIG. 1D, an instrument 99 is used to sever or pinch off a piece of the sectionalized, compartmentalized pliable material. The instrument 99 is shown as being a spatula. The extruded portion of the material is shown as being separated and pinched off from the unextruded portion at outlet end 16 of barrel 10. Support surface 88 of cutting plate 86 serves as a cutting surface against which instrument 99 is contacted in order to sever the piece of composite material extending beyond the outlet end 16 of the barrel 10. The spatula easily removes a discreet amount and regular shape of the pliable material in such a way that the piece of material is easily manageable and controllable upon the end of instrument 99.
When used in conjunction with light-cured composite materials, the barrel, divider, and cap of the prior art apparatus discussed above is preferably made of a material which blocks transmission of the activating light so that the material remains pliable until ready to use. For example, a black-colored substance may be used to block transmission of activating light. While the foregoing syringe apparatus provides for an improved method of applying light-activated dental composites, there is a possibility that when the spatula 99 contacts the support surface 88 of cutting plate 86 (or any other surface of the barrel or divider), such contact may scratch or graze the surface, such that small pieces of black colored plastic material are removed. These small pieces may fall into the composite material, thereby causing discoloration of the composite material and, consequently, of the final dental construction. It would, therefore, be an advantage in the art to prevent discoloration of the dental composite material when such composite material is extracted from a delivery syringe to provide for more attractive dental constructions.
The present invention has been developed in response to the current state of the art, and in particular, in response to these and other problems and needs that have not been fully or adequately solved with regard to syringes used to apply light-activated dental composites. Thus, it is an overall object of embodiments of the present invention to provide for a syringe apparatus which prevents discoloration of dental composites through the inadvertent removal of dark plastic material into the dental composite material.
A feature of the present invention that enables these objects and advantages to be achieved is the use of different colored surfaces. One surface protects the dental composite material or other light-activating material from premature exposure to light while the other surface has a light color that is similar to that of the dental composite material. More particularly, this configuration typically involves the use of an opaque syringe barrel and a light colored outlet portion. The outlet portion may have many different configurations, however, one embodiment is sleeve shaped and extends coaxially within the barrel. The color of the outlet portion is compatible with that of the dental composite material or is at least more similar to the color of the dental composite material as compared with the opaque barrel. This combination allows a dental instrument such as a spatula to be used to scoop small quantities of the dental composite material from the outlet portion without concern that any piece of the light colored outlet portion inadvertently scraped off from the outlet portion is not visually detectable in the dental composite material. Note that it is typically necessary to use a spatula to remove the dental composite material since the material is relatively thick and viscous.
The outlet portion may extend beyond the barrel so that the outlet end of the outlet portion extends further than the outlet end of the barrel. The outlet portion may include a divider at its outlet end that divides the material into at least two separate compartmentalized portions. Many other embodiments are discussed below; however, each involves the use of two different colored surfaces to protect the material from being activated before the use of the material is desired and to ensure that dark plastic particles are not inadvertently deposited into the material when removing the material from the syringe.
Any suitable plunger may be utilized. A cap is used to cover the outlet end of the barrel and the outlet portion. The cap is opaque to prevent light from passing through the outlet portion and prematurely activating the dental composite material or other light-activating material.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.